3 Best AGM Batteries (Review and Buying Guide)

Brace yourself for some cold autumn mornings! And of course, you’ll want to make sure your car’s ready as well. So what better way to do so than with the unrivaled CCA of an AGM battery?

These batteries will start your car on even the coldest of mornings. And if that’s not good enough, they leave no messes or leaks behind. Sound like a good deal? Then let’s find the best AGM battery for your car!

Here’s an Optima AGM that seemingly does it all! Packing high CCA, respectable reserve capacity, and plenty of durability, it’s ideal for most cars out there.

At a Glance

12-volt

800 CCA

10” x 6 78” x 7 1316”

38.8 lbs

Vibration resistant

Maintenance-free

100 min reserve capacity

The lifespan of about 2 years (more with good care)

Ideal for trucks, streetcars, SUVs, hot rods, and any other application.

Take a look at the specs above, and you’ll find this battery works great for most situations. But what those specs don’t show is how durable this battery is. We took it to the track and found it handled hard launches like a pro. No spills or dents in sight! Likewise, it’ll handle your off-roading needs just fine as well!

Something else that’s interesting to note here is that this battery is super easy to install. We tried three different cars, and each time it took a matter of seconds. So even if you’ve never replaced a gasket, you’ll fit this AGM in your car with ease!

One final note about this battery is that it’s perfect for your nicest show cars. During our tests, we found this battery could last months at a time without needing a trickle charge. So it’s great for that Challenger you only take out on the sunny weekends.

Optima Batteries OPT8020-164 35 RedTop Starting Battery

(3.8 / 5)

Here’s a battery that proves great things come in small packages. The Optima 35 RedTop’s compact size allows it to fit easily in most cars. But don’t let its size fool you. This battery also packs plenty of cranking power when it needs to!

At a Glance

12-volt

720 CCA

9.38” x 7.69” x 6.75”

31.7 lbs

90-minute reserve capacity

Lasts about 1-2 years (longer with good care)

The Optima Batteries OPT8020-164 battery, which is built for every road use, can work well at the ultra-low temperature.

Looking at this AGM’s size, you’ll notice it’s smaller than most other batteries on the market. So it’ll easily fit in a handful of cars. You’ll even get an adapter for easy height adjustments as well. This piece alone allowed us to snugly fit this battery inside a ’93 Mazda RX-7 with ease.

We also noticed that this battery felt like it offered more cranking amps compared to other batteries we’ve tested. It did an epic job of starting up our cars and keeping them going. So it’s definitely great even if you don’t live in a cold climate area!

Lastly, this AGM iswithout a doubt spill-proof, even more so than other AGMs. While not our most prideful moment, we hit our fair share of curbs and even a tire while testing. And each time, we noticed the battery never leaked or spilled. Even on a hot summer day, this battery never even made a trace of a mess!

Now here’s a battery that’s packing the power! Even by AGM standards, the CCA and reserve capacity are simply ridiculous here. And that’s a good thing!

At a Glance

12-volt

13.5” x 11” x 9.8”

50 lbs

850 CCA

130-minute reserve capacity

about 3-10 year lifespan

Providing twice as much power as a conventional battery.

Just look at those specs and you’ll find a freakish amount of CCA and reserve capacity here. Seriously, our car started instantly on a Colorado winter evening with no issues throughout the drive. So it’s a safe bet that it’ll do the same wherever you drive.

Also, this battery works great in cars with tons of after-market electronics. We tried it with a 3-amp bass system and noticed no light flickering. In fact, there were no electrical problems of any type. This becomes all the better when you factor in that high reserve capacity! Hence there’s plenty of room for fun here.

And lastly, you’ll get a reliably long lifespan with this battery. Take good care of it, and it’ll last every bit of 3 years and plenty more! So it’s definitely one of the longer lifespans compared to other AGMs.

Pros

Huge amount of CCA

Long lifespan

Super-long reserve capacity

Great for electronics

Decent Crank Power

Cons

Needs more time and amps to recharge

Heavy and bulky

What’s it Used for?

There’s no denying that all three of the above AGMs will offer something great for your car. And in truth, you could make a case for buying any of them. But if we’re being honest here, one stood out above the rest by a slight margin.

It’s really hard to ignore a battery that excels at everything a good AGM should do! Seriously, you’re getting enough CCA to power your car through any winter morning here. And its durability is more than enough for any drive you make.

Honestly, we can’t say enough good things about this battery. So whether you want to go off-roading in the snow, or own a battery that’s reliably there for you, the Optima 34/78 RedTop is a great choice!

Finding the Best AGM Battery

Before we take a look at the market’s best AGM batteries, let’s answer the first question on your mind. How do you know if it’s a good AGM battery in the first place?

Thankfully, we’ve got the answer right here in this buying guide. So here are some specs and features to prioritize when shopping for a car battery.

What are CCAs and How Many Do You Need?

CCA is an abbreviation for cold cranking amps. And the name really says it all. This value is what determines how well your battery starts your car in below-freezing temperatures. So it’s exactly what you’ll need for driving in these upcoming autumn and winter months.

As far as exact amounts go, it’ll vary. If you plan to drive your car in the cold weather, then you’ll want at least 700 or so. However, if you don’t plan to drive your car during bone-chilling times then this number is downright negligible.

Should You Opt For a High Reserve Capacity?

This one’s entirely up to you! But big numbers certainly won’t hurt! Especially for those times you leave your lights on during a grocery run. And you’ll definitely be thankful you have it the next time your friend makes a “quick” 7/11 run that lasts 45 minutes.

As a rule of thumb, 60 minutes is a good starting point. This way, you’ll have something to do anytime you need to wait in your car.

Is There a Right Battery Size for Your Car?

Much like all your other essentials, your car needs a certain battery size called a group. Don’t worry though, it’s pretty easy to find. Just check for the number on your current battery. And if that doesn’t work, consult your car’s manual.

If the above two don’t work, keep in mind that each size usually fits certain manufacturers. So your 34/78 is great for GM and Chrysler. Meanwhile, 35 is a great size for JDMs like Subaru and Nissan.

Maintenance-Free Makes Life Easy

Are you sick of your battery’s upkeep? Then opt for a maintenance-free!

These pack enough acid and chemicals to last your battery’s lifespan. So you might need to add some water from time to time. But they won’t require you to dirty your hands in any way! And once they run out of acid and chemicals, simply replace the battery.

Do You Need Special Batteries for Off-Roading?

The short answer is yes. But most of your AGMs have you covered. After all, they won’t really leak or make a mess when hitting a few bumps. However, it’s always best to check a battery’s durability before you climb some boulders with it.

What’s so Great About an AGM?

Also known as absorbed glass mats, these batteries are stellar for most cars out there!

For starters, they usually pack copious amounts of CCA to ensure your car starts perfectly in the cold weather. And even if you don’t live in a cold climate, AGMs are ideal for your non-dailies. So feel free to store that ’63 Nova away until car show season without needing to trickle charge in most cases.

Speaking of recharging, keep in mind that AGMs will generally do that faster than flooded batteries. And if that’s not enough, AGMs are designed in such a way that spilling, leaking, and corrosion are not issues! So you won’t need to clean up too many messes here.

And this is just the start of everything great AGMs (Sealed Absorbed Glass Mats) do for your car. Thus, there’s plenty of reasons you’ll want one.